package com.example.bootdemo.stack1;


import java.util.Scanner;

public class ArrayStackDemo1 {

    public static void main(String[] args) {
        //测试一下ArrayStack 是否正确
        //先创建一个ArrayStack对象->表示栈
        ArrayStack1 stack = new ArrayStack1(4);
        String key = "";
        boolean loop = true; //控制是否退出菜单
        Scanner scanner = new Scanner(System.in);

        while (loop) {
            System.out.println("show: 表示显示栈");
            System.out.println("exit: 退出程序");
            System.out.println("push: 表示添加数据到栈(入栈)");
            System.out.println("pop: 表示从栈取出数据(出栈)");
            System.out.println("请输入你的选择");
            key = scanner.next();
            switch (key) {
                case "show":
                    stack.list();
                    break;
                case "push":
                    System.out.println("请输入一个数");
                    int value = scanner.nextInt();
                    stack.push(value);
                    break;
                case "pop":
                    try {
                        int res = stack.pop();
                        System.out.printf("出栈的数据是 %d\n", res);
                    } catch (Exception e) {
                        // TODO: handle exception
                        System.out.println(e.getMessage());
                    }
                    break;
                case "exit":
                    scanner.close();
                    loop = false;
                    break;
                default:
                    break;
            }
        }

        System.out.println("程序退出~~~");
    }
}


    class ArrayStack1 {
        private final int maxSize; // 栈的大小
        private final int[] stack; // 数组，数组模拟栈，数据就放在该数组
        private int top = -1;// top表示栈顶，初始化为-1
        public ArrayStack1(int maxSize){
            this.maxSize=maxSize;
            this.stack= new int[maxSize];
        }
        //栈空
        public boolean isEmpty(){
            return top==-1;
        }
        //栈满
        public boolean isFull() {
            return this.top==maxSize-1;
        }
            //入栈-push
        public void push(int value) {
            if (isFull()){
                System.out.println("栈满");
                return;
            }
            this.top++;
            this.stack[this.top]=value;
        }
        //出栈-pop, 将栈顶的数据返回
        public int pop() {
            if (isEmpty()){
                System.out.println("栈空");
          throw new RuntimeException("栈空");
            }
           int a= this.stack[this.top];
            this.top--;
            return a;
        }
        //显示栈的情况[遍历栈]， 遍历时，需要从栈顶开始显示数据
        public void list() {
            if (isEmpty()){

                System.out.println("栈空");
               return;
            }
            for (int i = this.top; i >=0 ; i--) {
                System.out.println(this.stack[i]);
            }
        }

    }

